What are you talking about?
ACPI is Advanced Configuration and Power Interface for ATX-spec computers. There is no 'control cable'.
You have an ACPI-compliant motherboard, an ATX power supply, a momentary-on power switch, and an OS that supports ACPI (any OS released in the past 8 years or so falls into this category).
Have you looked in the FAQ yet?
How about the Wiki?
Under normal circumstances, a signature would go here.